The present invention relates to semiconductor devices, and more specifically, to forming an inter-level airgap between wiring traces on different levels of the device.
As VLSI chips have scaled over the decades, interconnect or wire width and spacing has also scaled. If not properly designed, this scaling can be a limiter of circuit performance. For example, unintended capacitive coupling between two wires that are next to each other can often occur. When this happens, one signal can capacitively couple with another and cause what appears to be noise.
Several different solutions have been attempted to reduce or eliminate such capacitance. The solutions include layout design and, in extreme cases, providing insulators between the wiring on a single level.